Automated identification and classification of intravascular lesions

ABSTRACT

Devices, systems, and methods of mapping a vessel system of a patient and identifying lesions therein are disclosed. This includes a method of evaluating a vessel of a patient, the method comprising obtaining image data for the vessel of the patient, obtaining physiological measurements for the vessel of the patient, co-registering the obtained physiological measurements with the obtained image data such that the physiological measurements are associated with corresponding portions of the vessel of the patient, analyzing the co-registered physiology measurements to determine a classification of a lesion within the vessel of the patient, and outputting, to a user interface, the classification of the lesion. Other associated methods, systems, and devices are also provided herein.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is continuation of U.S. patent application Ser.No. 14/961,656, filed Dec. 7, 2015, now U.S. Pat. No. 11,123,019, whichclaims priority to and the benefit of the U.S. Provisional PatentApplication No. 62/089,090, filed Dec. 8, 2014, which is herebyincorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to the assessment of vesselsfor percutaneous coronary intervention (PCI) planning. For example, someembodiments of the present disclosure are configured to automaticallylabel vessels of a patient in an image and identify and/or classifylesions present within the vessels to assist in diagnosing the. As aresult, treatment options can tailored to the specific characteristicsof the patient's lesion(s) and, thereby, improve the effectiveness ofpatient treatments.

BACKGROUND

Currently accepted techniques for assessing the severity of a stenosisin a blood vessel include obtaining images and physiologicalmeasurements of the vessel. For example, the severity of a stenosis issometimes observed visually and roughly estimated based on userexperience. For example, a patient's vasculature can be visualized usingangiography. However, even with experience and expertise, the locationsof stenoses in a vessel can be difficult to visualize in a grayscaleangiographic image. The use of pressure data can improve theinterpretation of information gleaned from an angiogram. For example,fractional flow reserve (FFR) and/or instantaneous wave-free ratio (iFR)can be utilized to estimate the severity of a stenosis. FFR and iFR arecalculations of the ratio of a distal pressure measurement (taken on thedistal side of the stenosis) relative to a proximal pressure measurement(taken on the proximal side of the stenosis). Both FFR and iFR providean index of stenosis severity that allows determination as to whetherthe blockage significantly limits blood flow within the vessel to anextent that treatment is required. Further, a more complete diagnosis ofthe patient can be made by also performing intravascular imaging, suchas intravascular ultrasound (IVUS) or optical coherence tomography(OCT). For example, in some instances intravascular imaging can beutilized to provide a cross-sectional image of the vessel and/orcharacterize the type(s) of tissue/plaque present in a stenosis. Due tothe variations and, often, lack of clarity in angiographic andintravascular images, these diagnostic techniques require extensivetraining and experience before a user can confidently identifyparticular vessels, let alone identify and classify lesions within thosevessels. However, the limited amount of time for training new medicalpersonnel results in many patients becoming de facto training cases forthe medical personnel, which can result in misidentification of vessels,failure to identify significant lesions, and/or misclassification ofidentified lesions. As a result, the treatment plans selected for thepatient may not be optimized for the patient's actual medical needs.

Accordingly, there remains a need for improved devices, systems, andmethods for assessing the severity of a blockage in a vessel and, inparticular, a stenosis in a blood vessel. Moreover, there remains a needfor improved devices, systems, and methods of automatically mappingvessel systems, identifying potential lesions in the vessel system, andclassifying the identified lesions in a user friendly manner.

SUMMARY

Embodiments of the present disclosure are directed to mapping a vesselsystem of a patient and identifying lesions therein. One general aspectincludes a method of evaluating a vessel of a patient, the methodcomprising: obtaining image data for the vessel of the patient;obtaining physiological measurements for the vessel of the patient;co-registering the obtained physiological measurements with the obtainedimage data such that the physiological measurements are associated withcorresponding portions of the vessel of the patient; analyzing theco-registered physiology measurements to determine a classification of alesion within the vessel of the patient; and outputting, to a userinterface, the classification of the lesion.

In one embodiment, the above method further comprises analyzing theco-registered physiology measurements to determine a location of thelesion within the vessel of the patient. Furthermore, outputting theclassification of the lesion to the user interface may includeoverlaying a representation of the classification onto an image of thevessel in proximity of the location of the lesion. The method mayfurther comprise analyzing the obtained image data to identify a vesselname for the vessel and outputting, to the user interface, the vesselname in proximity to the vessel.

In an aspect, analyzing the obtained image data to identify the vesselname for the vessel includes utilizing a computer aided detectionalgorithm. The obtained image data may include image data received froman extravascular imaging system. Furthermore, the obtained image datamay include at least one of a two-dimensional angiographic image, athree-dimensional angiographic image, or a computed tomographyangiographic (CTA) image. The obtained physiological measurements mayinclude pressure measurements, and at least some of the obtainedpressure measurements may be obtained at multiple locations along thevessel. The obtained physiological measurements may also include flowmeasurements.

A system for evaluating a vessel of a patient is also provided, thesystem comprising: a processing system in communication with at leastone intravascular device, the processing system configured to: obtainimage data for the vessel of the patient; obtain physiologicalmeasurements for the vessel of the patient; co-register the obtainedphysiological measurements with the obtained image data such that thephysiological measurements are associated with corresponding portions ofthe vessel of the patient; analyze the co-registered physiologymeasurements to determine a classification of a lesion within the vesselof the patient; and output, to a user interface, the classification ofthe lesion.

In an aspect, the processing system is further configured to analyze theco-registered physiology measurements to determine a location of thelesion within the vessel of the patient. Furthermore, the processingsystem may be configured to output the classification of the lesion tothe user interface by overlaying a representation of the classificationonto an image of the vessel in proximity of the location of the lesion.The processing system may be further configured to analyze the obtainedimage data to identify a vessel name for the vessel and output, to theuser interface, the vessel name in proximity to the vessel.

In one embodiment, the processing system utilizes a computer aideddetection algorithm to identify the vessel name for the vessel.Furthermore, the obtained image data may include image data receivedfrom an extravascular imaging system, or at least one of atwo-dimensional angiographic image, a three-dimensional angiographicimage, or a computed tomography angiographic (CTA) image. In an aspect,the at least one intravascular devices includes a pressure-sensingintravascular device and wherein the obtained physiological measurementsinclude pressure measurements. The processing system may be furtherconfigured to calculate a pressure ratio based on the obtained pressuremeasurements. The at least one intravascular devices may also include aflow-sensing intravascular device and wherein the obtained physiologicalmeasurements include flow measurements.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present disclosure will be describedwith reference to the accompanying drawings, of which:

FIG. 1 is a diagrammatic perspective view of a vessel having a stenosisaccording to an embodiment of the present disclosure.

FIG. 2 is a diagrammatic, partial cross-sectional perspective view of aportion of the vessel of FIG. 1 taken along section line 2-2 of FIG. 1.

FIG. 3 is a diagrammatic, partial cross-sectional perspective view ofthe vessel of FIGS. 1 and 2 with instruments positioned thereinaccording to an embodiment of the present disclosure.

FIG. 4 is a diagrammatic, schematic view of a system according to anembodiment of the present disclosure.

FIG. 5 is a stylized image of a patient's vasculature as seen in anangiogram image on a user interface according to an embodiment of thepresent disclosure.

FIG. 6 is an annotated version of a patient's vasculature as seen in anangiogram image on a user interface according to an embodiment of thepresent disclosure.

FIG. 7 is an annotated version of a patient's vasculature as seen in anangiogram image on a user interface according to another embodiment ofthe present disclosure.

FIG. 8 is an annotated version of a patient's vasculature as seen in anangiogram image on a user interface according to another embodiment ofthe present disclosure

FIG. 9 is a graphical user interface screen display according to anembodiment of the present disclosure.

FIG. 10 is a series of stylized images of a vessel illustratingclassification of vessel obstructions according to an embodiment of thepresent disclosure.

FIG. 11 is a flow diagram of a method for identify and classifyinglesions with an vessel system according to an embodiment of the presentdisclosure.

These drawings may be better understood by reference to the followingdetailed description.

DETAILED DESCRIPTION

For the purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It is nevertheless understood that no limitation tothe scope of the disclosure is intended. Any alterations and furthermodifications to the described devices, systems, and methods, and anyfurther application of the principles of the present disclosure arefully contemplated and included within the present disclosure as wouldnormally occur to one skilled in the art to which the disclosurerelates. In particular, it is fully contemplated that the features,components, and/or steps described with respect to one embodiment may becombined with the features, components, and/or steps described withrespect to other embodiments of the present disclosure. For the sake ofbrevity, however, the numerous iterations of these combinations will notbe described separately.

Physiological measurement data and the coronary angiogram typicallybehave as complementary, yet segregated sources of information. Thecoronary angiogram has been used to make treatment decisions. Morerecently, physiological data (including, but not limited to, pressureand/or flow measurements, both at hyperemia and rest) have shown thatbetter decisions can be made based on the severity of a blockage bymeasuring the change in underlying physiological conditions from thebeginning of a target artery to the end. Treating a patient based on theseverity of this change or delta has shown to improve outcomes andreduce waste from unnecessary procedures. In one or more aspects of thepresent disclosure, the physiological data, as collected real-time, islinked or co-registered to a schematic of the coronary arteries or anangiogram. At this point, a computer aided detection algorithm can beapplied to the data to identify and map coronary vessels. Physiologicalmeasurements obtained from within the vessels can then be compared tothe map to identify lesion locations. Further, the physiologicalmeasurements can be utilized to determine a length and/or classify theidentified lesions. In making the classification, data representing thelesion sites may also be visually depicted in a way that allows aclinician to interact and assess the severity and/or boundaries of thelesion. Furthermore, the identification and classification of thelesions in the vessel system can be displayed to a clinician on a userinterface. Among other benefits, the identification and classificationof the lesions can permit a clinician to plan a percutaneous coronaryintervention tailored to the specific lesion characteristics of thepatient.

Referring to FIGS. 1 and 2, shown therein is a vessel 100 having astenosis according to an embodiment of the present disclosure. In thatregard, FIG. 1 is a diagrammatic perspective view of the vessel 100,while FIG. 2 is a partial cross-sectional perspective view of a portionof the vessel 100 taken along section line 2-2 of FIG. 1. Referring morespecifically to FIG. 1, the vessel 100 includes a proximal portion 102and a distal portion 104. A lumen 106 extends along the length of thevessel 100 between the proximal portion 102 and the distal portion 104.In that regard, the lumen 106 is configured to allow the flow of fluidthrough the vessel. In some instances, the vessel 100 is a blood vessel.In some particular instances, the vessel 100 is a coronary artery. Insuch instances, the lumen 106 is configured to facilitate the flow ofblood through the vessel 100.

As shown, the vessel 100 includes a stenosis 108 between the proximalportion 102 and the distal portion 104. Stenosis 108 is generallyrepresentative of any blockage or other structural arrangement thatresults in a restriction to the flow of fluid through the lumen 106 ofthe vessel 100. Embodiments of the present disclosure are suitable foruse in a wide variety of vascular applications, including withoutlimitation coronary, peripheral (including but not limited to lowerlimb, carotid, and neurovascular), renal, and/or venous. Where thevessel 100 is a blood vessel, the stenosis 108 may be a result of plaquebuildup, including without limitation plaque components such as fibrous,fibro-lipidic (fibro fatty), necrotic core, calcified (dense calcium),blood, fresh thrombus, and mature thrombus. Generally, the compositionof the stenosis will depend on the type of vessel being evaluated. Inthat regard, it is understood that the concepts of the presentdisclosure are applicable to virtually any type of blockage or othernarrowing of a vessel that results in decreased fluid flow.

Referring more particularly to FIG. 2, the lumen 106 of the vessel 100has a diameter 110 proximal of the stenosis 108 and a diameter 112distal of the stenosis. In some instances, the diameters 110 and 112 aresubstantially equal to one another. In that regard, the diameters 110and 112 are intended to represent healthy portions, or at leasthealthier portions, of the lumen 106 in comparison to stenosis 108.Accordingly, these healthier portions of the lumen 106 are illustratedas having a substantially constant cylindrical profile and, as a result,the height or width of the lumen has been referred to as a diameter.However, it is understood that in many instances these portions of thelumen 106 will also have plaque buildup, a non-symmetric profile, and/orother irregularities, but to a lesser extent than stenosis 108 and,therefore, will not have a cylindrical profile. In such instances, thediameters 110 and 112 are understood to be representative of a relativesize or cross-sectional area of the lumen and do not imply a circularcross-sectional profile.

As shown in FIG. 2, stenosis 108 includes plaque buildup 114 thatnarrows the lumen 106 of the vessel 100. In some instances, the plaquebuildup 114 does not have a uniform or symmetrical profile, makingangiographic evaluation of such a stenosis unreliable. In theillustrated embodiment, the plaque buildup 114 includes an upper portion116 and an opposing lower portion 118. In that regard, the lower portion118 has an increased thickness relative to the upper portion 116 thatresults in a non-symmetrical and non-uniform profile relative to theportions of the lumen proximal and distal of the stenosis 108. As shown,the plaque buildup 114 decreases the available space for fluid to flowthrough the lumen 106. In particular, the cross-sectional area of thelumen 106 is decreased by the plaque buildup 114. At the narrowest pointbetween the upper and lower portions 116, 118 the lumen 106 has a height120, which is representative of a reduced size or cross-sectional arearelative to the diameters 110 and 112 proximal and distal of thestenosis 108. Note that the stenosis 108, including plaque buildup 114is exemplary in nature and should be considered limiting in any way. Inthat regard, it is understood that the stenosis 108 has other shapesand/or compositions that limit the flow of fluid through the lumen 106in other instances. While the vessel 100 is illustrated in FIGS. 1 and 2as having a single stenosis 108 and the description of the embodimentsbelow is primarily made in the context of a single stenosis, it isnevertheless understood that the devices, systems, and methods describedherein have similar application for a vessel having multiple stenosisregions.

Referring now to FIG. 3, the vessel 100 is shown with instruments 130and 132 positioned therein according to an embodiment of the presentdisclosure. In general, instruments 130 and 132 may be any form ofdevice, instrument, or probe sized and shaped to be positioned within avessel. In the illustrated embodiment, instrument 130 is generallyrepresentative of a guide wire, while instrument 132 is generallyrepresentative of a catheter. In that regard, instrument 130 extendsthrough a central lumen of instrument 132. However, in otherembodiments, the instruments 130 and 132 take other forms. In thatregard, the instruments 130 and 132 are of similar form in someembodiments. For example, in some instances, both instruments 130 and132 are guide wires. In other instances, both instruments 130 and 132are catheters. On the other hand, the instruments 130 and 132 are ofdifferent form in some embodiments, such as the illustrated embodiment,where one of the instruments is a catheter and the other is a guidewire. Further, in some instances, the instruments 130 and 132 aredisposed coaxial with one another, as shown in the illustratedembodiment of FIG. 3. In other instances, one of the instruments extendsthrough an off-center lumen of the other instrument. In yet otherinstances, the instruments 130 and 132 extend side-by-side. In someparticular embodiments, at least one of the instruments is as arapid-exchange device, such as a rapid-exchange catheter. In suchembodiments, the other instrument is a buddy wire or other deviceconfigured to facilitate the introduction and removal of therapid-exchange device. Further still, in other instances, instead of twoseparate instruments 130 and 132 a single instrument is utilized. Insome embodiments, the single instrument incorporates aspects of thefunctionalities (e.g., data acquisition) of both instruments 130 and132.

Instrument 130 is configured to obtain diagnostic information about thevessel 100. In that regard, the instrument 130 includes one or moresensors, transducers, and/or other monitoring elements configured toobtain the diagnostic information about the vessel. The diagnosticinformation includes one or more of pressure, flow (velocity and/orvolume), images (including images obtained using ultrasound (e.g.,IVUS), OCT, thermal, and/or other imaging techniques), temperature,and/or combinations thereof. The one or more sensors, transducers,and/or other monitoring elements are positioned adjacent a distalportion of the instrument 130 in some instances. In that regard, the oneor more sensors, transducers, and/or other monitoring elements arepositioned less than 30 cm, less than 10 cm, less than 5 cm, less than 3cm, less than 2 cm, and/or less than 1 cm from a distal tip 134 of theinstrument 130 in some instances. In some instances, at least one of theone or more sensors, transducers, and/or other monitoring elements ispositioned at the distal tip of the instrument 130.

The instrument 130 can include at least one element configured tomonitor pressure within the vessel 100. The pressure monitoring elementcan take the form a piezo-resistive pressure sensor, a piezo-electricpressure sensor, a capacitive pressure sensor, an electromagneticpressure sensor, a fluid column (the fluid column being in communicationwith a fluid column sensor that is separate from the instrument and/orpositioned at a portion of the instrument proximal of the fluid column),an optical pressure sensor, and/or combinations thereof. In someinstances, one or more features of the pressure monitoring element areimplemented as a solid-state component manufactured using semiconductorand/or other suitable manufacturing techniques. Examples of commerciallyavailable guide wire products that include suitable pressure monitoringelements include, without limitation, the Verrata® pressure guide wire,the PrimeWire Prestige® PLUS pressure guide wire, and the ComboWire® XTpressure and flow guide wire, each available from Volcano Corporation,as well as the PressureWire′ Certus guide wire and the PressureWire™Aeris guide wire, each available from St. Jude Medical, Inc. Generally,the instrument 130 is sized such that it can be positioned through thestenosis 108 without significantly impacting fluid flow across thestenosis, which would impact the distal pressure reading. Accordingly,in some instances the instrument 130 has an outer diameter of 0.018″ orless. In some embodiments, the instrument 130 has an outer diameter of0.014″ or less. In some embodiments, the instrument 130 has an outerdiameter of 0.035″ or less.

Instrument 132 is also configured to obtain diagnostic information aboutthe vessel 100. In some instances, instrument 132 is configured toobtain the same diagnostic information as instrument 130. In otherinstances, instrument 132 is configured to obtain different diagnosticinformation than instrument 130, which may include additional diagnosticinformation, less diagnostic information, and/or alternative diagnosticinformation. The diagnostic information obtained by instrument 132includes one or more of pressure, flow (velocity and/or volume), images(including images obtained using ultrasound (e.g., IVUS), OCT, thermal,and/or other imaging techniques), temperature, and/or combinationsthereof. Instrument 132 includes one or more sensors, transducers,and/or other monitoring elements configured to obtain this diagnosticinformation. In that regard, the one or more sensors, transducers,and/or other monitoring elements are positioned adjacent a distalportion of the instrument 132 in some instances. In that regard, the oneor more sensors, transducers, and/or other monitoring elements arepositioned less than 30 cm, less than 10 cm, less than 5 cm, less than 3cm, less than 2 cm, and/or less than 1 cm from a distal tip 136 of theinstrument 132 in some instances. In some instances, at least one of theone or more sensors, transducers, and/or other monitoring elements ispositioned at the distal tip of the instrument 132.

Similar to instrument 130, instrument 132 can also include at least oneelement configured to monitor pressure within the vessel 100. Thepressure monitoring element can take the form a piezo-resistive pressuresensor, a piezo-electric pressure sensor, a capacitive pressure sensor,an electromagnetic pressure sensor, a fluid column (the fluid columnbeing in communication with a fluid column sensor that is separate fromthe instrument and/or positioned at a portion of the instrument proximalof the fluid column), an optical pressure sensor, and/or combinationsthereof. In some instances, one or more features of the pressuremonitoring element are implemented as a solid-state componentmanufactured using semiconductor and/or other suitable manufacturingtechniques. Currently available catheter products suitable for use withone or more of Siemens AXIOM Sensis, Mennen Horizon XVu, and PhilipsXper IM Physiomonitoring 5 and include pressure monitoring elements canbe utilized for instrument 132 in some instances.

In accordance with aspects of the present disclosure, at least one ofthe instruments 130 and 132 is configured to monitor a pressure withinthe vessel 100 distal of the stenosis 108 and at least one of theinstruments 130 and 132 is configured to monitor a pressure within thevessel proximal of the stenosis. In that regard, the instruments 130,132 are sized and shaped to allow positioning of the at least oneelement configured to monitor pressure within the vessel 100 to bepositioned proximal and/or distal of the stenosis 108 as necessary basedon the configuration of the devices. In that regard, FIG. 3 illustratesa position 138 suitable for measuring pressure distal of the stenosis108. In that regard, the position 138 is less than 5 cm, less than 3 cm,less than 2 cm, less than 1 cm, less than 5 mm, and/or less than 2.5 mmfrom the distal end of the stenosis 108 (as shown in FIG. 2) in someinstances. FIG. 3 also illustrates a plurality of suitable positions formeasuring pressure proximal of the stenosis 108. In that regard,positions 140, 142, 144, 146, and 148 each represent a position that issuitable for monitoring the pressure proximal of the stenosis in someinstances. In that regard, the positions 140, 142, 144, 146, and 148 arepositioned at varying distances from the proximal end of the stenosis108 ranging from more than 20 cm down to about 5 mm or less. Generally,the proximal pressure measurement will be spaced from the proximal endof the stenosis. Accordingly, in some instances, the proximal pressuremeasurement is taken at a distance equal to or greater than an innerdiameter of the lumen of the vessel from the proximal end of thestenosis. In the context of coronary artery pressure measurements, theproximal pressure measurement is generally taken at a position proximalof the stenosis and distal of the aorta, within a proximal portion ofthe vessel. However, in some particular instances of coronary arterypressure measurements, the proximal pressure measurement is taken from alocation inside the aorta. In other instances, the proximal pressuremeasurement is taken at the root or ostium of the coronary artery.

In some embodiments, at least one of the instruments 130 and 132 isconfigured to monitor pressure within the vessel 100 while being movedthrough the lumen 106. In some instances, instrument 130 is configuredto be moved through the lumen 106 and across the stenosis 108. In thatregard, the instrument 130 is positioned distal of the stenosis 108 andmoved proximally (i.e., pulled back) across the stenosis to a positionproximal of the stenosis in some instances. In other instances, theinstrument 130 is positioned proximal of the stenosis 108 and moveddistally across the stenosis to a position distal of the stenosis.Movement of the instrument 130, either proximally or distally, iscontrolled manually by medical personnel (e.g., hand of a surgeon) insome embodiments. In other embodiments, movement of the instrument 130,either proximally or distally, is controlled automatically by a movementcontrol device (e.g., a pullback device, such as the Trak Back® IIDevice available from Volcano Corporation). In that regard, the movementcontrol device controls the movement of the instrument 130 at aselectable and known speed (e.g., 2.0 mm/s, 1.0 mm/s, 0.5 mm/s, 0.2mm/s, etc.) in some instances. Movement of the instrument 130 throughthe vessel is continuous for each pullback or push through, in someinstances. In other instances, the instrument 130 is moved step-wisethrough the vessel (i.e., repeatedly moved a fixed amount of distanceand/or a fixed amount of time). Some aspects of the visual depictionsdiscussed below are particularly suited for embodiments where at leastone of the instruments 130 and 132 is moved through the lumen 106.Further, in some particular instances, aspects of the visual depictionsdiscussed below are particularly suited for embodiments where a singleinstrument is moved through the lumen 106, with or without the presenceof a second instrument.

The instruments 130 and/or 132 can be used to conduct medical sensingprocedures associated with Instant Wave-Free Ratio™ Functionality (iFR®Functionality) (both trademarks of Volcano Corp.) and those disclosed inU.S. patent application Ser. No. 13/460,296, entitled “DEVICES, SYSTEMS,AND METHODS FOR ASSESSING A VESSEL,” hereby incorporated by reference inits entirety, which discloses the use of pressure ratios that areavailable without application of a hyperemic agent. Further, medicalsensing procedures associated with compensated Pd/Pa ratios suitable forestimating iFR®, FFR, and/or other accepted diagnostic pressure ratiosas disclosed in U.S. Provisional Patent Application No. 62/024,005,filed Jul. 14, 2014 and entitled “DEVICES, SYSTEMS, AND METHODS FORTREATMENT OF VESSELS,” which is hereby incorporated by reference in itsentirety, can be conducted using the instruments 130 and/or 132.

Referring now to FIG. 4, shown therein is a system 150 according to anembodiment of the present disclosure. In that regard, FIG. 4 is adiagrammatic, schematic view of the system 150. As shown, the system 150includes an instrument 152. In that regard, in some instances instrument152 is suitable for use as at least one of instruments 130 and 132discussed above. Accordingly, in some instances the instrument 152includes features similar to those discussed above with respect toinstruments 130 and 132 in some instances. In the illustratedembodiment, the instrument 152 is a guide wire having a distal portion154 and a housing 156 positioned adjacent the distal portion. In thatregard, the housing 156 is spaced approximately 3 cm from a distal tipof the instrument 152. The housing 156 is configured to house one ormore sensors, transducers, and/or other monitoring elements configuredto obtain the diagnostic information about the vessel. In theillustrated embodiment, the housing 156 contains at least a pressuresensor configured to monitor a pressure within a lumen in which theinstrument 152 is positioned. A shaft 158 extends proximally from thehousing 156. A torque device 160 is positioned over and coupled to aproximal portion of the shaft 158. A proximal end portion 162 of theinstrument 152 is coupled to a connector 164. A cable 166 extends fromconnector 164 to a connector 168. In some instances, connector 168 isconfigured to be plugged into an interface 170. In that regard,interface 170 is a patient interface module (PIM) in some instances. Insome instances, the cable 166 is replaced with a wireless connection. Inthat regard, it is understood that various communication pathwaysbetween the instrument 152 and the interface 170 may be utilized,including physical connections (including electrical, optical, and/orfluid connections), wireless connections, and/or combinations thereof.

The interface 170 is communicatively coupled to a computing device 172via a connection 174. Computing device 172 is generally representativeof any device suitable for performing the processing and analysistechniques discussed within the present disclosure. In some embodiments,the computing device 172 includes a processor, random access memory, anda storage medium. In that regard, in some particular instances thecomputing device 172 is programmed to execute steps associated with thedata acquisition and analysis described herein. Accordingly, it isunderstood that any steps related to data acquisition, data processing,instrument control, and/or other processing or control aspects of thepresent disclosure may be implemented by the computing device usingcorresponding instructions stored on or in a non-transitory computerreadable medium accessible by the computing device. In some instances,the computing device 172 is a console device. In some particularinstances, the computing device 172 is similar to the s5 Imaging Systemor the s5i Imaging System, each available from Volcano Corporation. Insome instances, the computing device 172 is portable (e.g., handheld, ona rolling cart, etc.). In some instances, all or a portion of thecomputing device 172 can be implemented as a bedside controller suchthat one or more processing steps described herein can be performed byprocessing component(s) of the bedside controller. An exemplary bedsidecontroller is described in U.S. Provisional Application No. 62/049,265,titled “Bedside Controller for Assessment of Vessels and AssociatedDevices, Systems, and Methods,” and filed Sep. 11, 2014, the entirety ofwhich is hereby incorporated by reference herein. Further, it isunderstood that in some instances the computing device 172 comprises aplurality of computing devices. In that regard, it is particularlyunderstood that the different processing and/or control aspects of thepresent disclosure may be implemented separately or within predefinedgroupings using a plurality of computing devices. Any divisions and/orcombinations of the processing and/or control aspects described belowacross multiple computing devices are within the scope of the presentdisclosure.

Together, connector 164, cable 166, connector 168, interface 170, andconnection 174 facilitate communication between the one or more sensors,transducers, and/or other monitoring elements of the instrument 152 andthe computing device 172. However, this communication pathway isexemplary in nature and should not be considered limiting in any way. Inthat regard, it is understood that any communication pathway between theinstrument 152 and the computing device 172 may be utilized, includingphysical connections (including electrical, optical, and/or fluidconnections), wireless connections, and/or combinations thereof. In thatregard, it is understood that the connection 174 is wireless in someinstances. In some instances, the connection 174 includes acommunication link over a network (e.g., intranet, internet,telecommunications network, and/or other network). In that regard, it isunderstood that the computing device 172 is positioned remote from anoperating area where the instrument 152 is being used in some instances.Having the connection 174 include a connection over a network canfacilitate communication between the instrument 152 and the remotecomputing device 172 regardless of whether the computing device is in anadjacent room, an adjacent building, or in a different state/country.Further, it is understood that the communication pathway between theinstrument 152 and the computing device 172 is a secure connection insome instances. Further still, it is understood that, in some instances,the data communicated over one or more portions of the communicationpathway between the instrument 152 and the computing device 172 isencrypted.

The system 150 also includes an instrument 175. In that regard, in someinstances instrument 175 is suitable for use as at least one ofinstruments 130 and 132 discussed above. Accordingly, in some instancesthe instrument 175 includes features similar to those discussed abovewith respect to instruments 130 and 132 in some instances. In theillustrated embodiment, the instrument 175 is a catheter-type device. Inthat regard, the instrument 175 includes one or more sensors,transducers, and/or other monitoring elements adjacent a distal portionof the instrument configured to obtain the diagnostic information aboutthe vessel. In the illustrated embodiment, the instrument 175 includes apressure sensor configured to monitor a pressure within a lumen in whichthe instrument 175 is positioned. The instrument 175 is in communicationwith an interface 176 via connection 177. In some instances, interface176 is a hemodynamic monitoring system or other control device, such asSiemens AXIOM Sensis, Mennen Horizon XVu, and Philips Xper IMPhysiomonitoring 5. In one particular embodiment, instrument 175 is apressure-sensing catheter that includes fluid column extending along itslength. In such an embodiment, interface 176 includes a hemostasis valvefluidly coupled to the fluid column of the catheter, a manifold fluidlycoupled to the hemostasis valve, and tubing extending between thecomponents as necessary to fluidly couple the components. In thatregard, the fluid column of the catheter is in fluid communication witha pressure sensor via the valve, manifold, and tubing. In someinstances, the pressure sensor is part of interface 176. In otherinstances, the pressure sensor is a separate component positionedbetween the instrument 175 and the interface 176. The interface 176 iscommunicatively coupled to the computing device 172 via a connection178.

The computing device 172 is communicatively coupled to a display device180 via a connection 182. In some embodiments, the display device 172 isa component of the computing device 172, while in other embodiments, thedisplay device 172 is distinct from the computing device 172. In someembodiments, the display device 172 is implemented as a bedsidecontroller having a touch-screen display as described, for example, inU.S. Provisional Application No. 62/049,265, titled “Bedside Controllerfor Assessment of Vessels and Associated Devices, Systems, and Methods,”and filed Sep. 11, 2014, the entirety of which is hereby incorporated byreference herein. The computing device 172 can generate screen displaysincluding data collected by the instruments 152 and 175 and otherinstruments, quantities computed based on the collected data,visualizations of the vessel in which the data is collected, andvisualizations based on the collected data and computed quantities.Exemplary screen displays are illustrated in FIGS. 5 and 7. Thecomputing device 172 can provide the display data associated with thescreen displays to the display device 180.

The computing device 172 can additionally be communicatively coupled toa user interface device. The user interface device permits a user tointeract with the screen displays on the display device 180. Forexample, the user can provide a user input to modify all or a portion ofthe screen display using the user interface device. Exemplary userinputs and the corresponding modifications to the screen display areillustrated in FIGS. 5 and 7. In some embodiments, the user interfacedevice is a separate component from the display device 180. In otherembodiments, the user interface device is part of the display device180. For example, the user interface device can be implemented as abedside controller having a touch-screen display as described, forexample, in U.S. Provisional Application No. 62/049,265, titled “BedsideController for Assessment of Vessels and Associated Devices, Systems,and Methods,” and filed Sep. 11, 2014, the entirety of which is herebyincorporated by reference herein. In such embodiments, a user input canbe a touch input received on the touch sensitive display of the bedsidecontroller.

Similar to the connections between instrument 152 and the computingdevice 172, interface 176 and connections 177 and 178 facilitatecommunication between the one or more sensors, transducers, and/or othermonitoring elements of the instrument 175 and the computing device 172.However, this communication pathway is exemplary in nature and shouldnot be considered limiting in any way. In that regard, it is understoodthat any communication pathway between the instrument 175 and thecomputing device 172 may be utilized, including physical connections(including electrical, optical, and/or fluid connections), wirelessconnections, and/or combinations thereof. In that regard, it isunderstood that the connection 178 is wireless in some instances. Insome instances, the connection 178 includes a communication link over anetwork (e.g., intranet, internet, telecommunications network, and/orother network). In that regard, it is understood that the computingdevice 172 is positioned remote from an operating area where theinstrument 175 is being used in some instances. Having the connection178 include a connection over a network can facilitate communicationbetween the instrument 175 and the remote computing device 172regardless of whether the computing device is in an adjacent room, anadjacent building, or in a different state/country. Further, it isunderstood that the communication pathway between the instrument 175 andthe computing device 172 is a secure connection in some instances.Further still, it is understood that, in some instances, the datacommunicated over one or more portions of the communication pathwaybetween the instrument 175 and the computing device 172 is encrypted.

It is understood that one or more components of the system 150 are notincluded, are implemented in a different arrangement/order, and/or arereplaced with an alternative device/mechanism in other embodiments ofthe present disclosure. For example, in some instances, the system 150does not include interface 170 and/or interface 176. In such instances,the connector 168 (or other similar connector in communication withinstrument 152 or instrument 175) may plug into a port associated withcomputing device 172. Alternatively, the instruments 152, 175 maycommunicate wirelessly with the computing device 172. Generallyspeaking, the communication pathway between either or both of theinstruments 152, 175 and the computing device 172 may have nointermediate nodes (i.e., a direct connection), one intermediate nodebetween the instrument and the computing device, or a plurality ofintermediate nodes between the instrument and the computing device.

In some embodiments, the system 150 can additionally include a bedsidecontroller, such as the bedside controller described in U.S. ProvisionalApplication No. 62/049,265, titled “Bedside Controller for Assessment ofVessels and Associated Devices, Systems, and Methods,” and filed Sep.11, 2014, the entirety of which is hereby incorporated by referenceherein. The bedside controller may be utilized by a clinician to controlinstruments 152 and 175 to acquire pressure data during a procedure,watch real-time medical pressure measurements (e.g., visualrepresentations of pressure data, such as pressure waveforms, numericalvalues, etc.), compute pressure ratio(s) based on the collected pressuredata, and interact with the obtained medical sensing data, a visualrepresentation of the obtained medical sensing data and/or computedpressure ratio(s), a visualization based on the obtained medical sensingdata and/or computed pressure ratio(s), and/or a visual representationof the vessel 100. In that regard, the bedside controller can becommunicatively coupled to the computing device 172, the interfaces 170and 176, and/or the instruments 152 and 175.

In some embodiments, the system 150 can include an inventory database190 associated with a clinical environment, such as a hospital or otherhealthcare facility at which a PCI would be carried out on a patient.The inventory database can store various data about stents that areavailable to a clinician for use. The data can include manufacturernames, length, diameter, material, quantity available at the hospital,quantity available for immediate use, resupply frequency, next shipmentdate, and other suitable information. The computing device 172 cancompile a plurality of stent options based on the inventory database 190and provide a selection menu to the clinician. The computing device 172can provide automatically recommend a particular stent (e.g., a stentfrom a particular manufacturer, with a particular length, diameter,and/or material) based on the PCI planning conducted using the graphicaluser interface. The computing device 172 can also receive a user inputselecting a particular stent and provide it into the graphical userinterface such that a clinician can assess the efficacy of treatmentusing the selected stent. The computing device 172 is communicativelycoupled to the inventory database 190 via a connection 192. Theconnection 192 can be representative of one or more network connectionsthat communicatively couple the computing device 172 with a computingsystem of the healthcare facility.

The diagnostic information and/or data obtained by instruments 130, 132,152, and/or 175 are correlated or co-registered to angiographic image(s)and/or other two-dimensional or three-dimensional depictions of apatient's vasculature obtained by an external imaging system. In variousembodiments, the diagnostic information obtained by the external imagingsystem can include externally-obtained angiographic images, x-rayimages, CT images, PET images, MM images, SPECT images, and/or othertwo-dimensional or three-dimensional extraluminal depictions of apatient's vasculature. Spatial co-registration can be completed usingtechniques disclosed in U.S. Pat. No. 7,930,014, titled “VASCULAR IMAGECO-REGISTRATION,” which is hereby incorporated by reference in itsentirety, based on the known pullback speed/distance, based on a knownstarting point, based on a known ending point, and/or combinationsthereof. For example, a mechanical pullback device can be used toconduct the pressure-sensing procedure. The mechanical pullback devicecan move the pressure-sensing device through the vessel at a fixed,known rate. The location of the pressure measurements and/or thepressure ratio(s) can be determined based on the rate of the pullbackand a known location of the pressure-sensing device (e.g., a startposition, a mid-point position, an end position, available fromangiography data). In some embodiments, diagnostic information and/ordata is correlated to vessel images using techniques similar to thosedescribed in U.S. Provisional Patent Application No. 61/747,480, titled“SPATIAL CORRELATION OF INTRAVASCULAR IMAGES AND PHYSIOLOGICAL FEATURES”and filed Dec. 31, 2012, which is hereby incorporated by reference inits entirety. In some embodiments, co-registration and/or correlationcan be completed as described in U.S. Provisional Patent Application No.61/856,509, titled “DEVICES, SYSTEMS, AND METHODS FOR ASSESSMENT OFVESSELS” and filed Jul. 19, 2013, which is hereby incorporated byreference in its entirety.

In some embodiments, diagnostic information and/or data is correlated tovessel images using techniques similar to those described in U.S. patentapplication Ser. No. 14/144,280, titled “DEVICES, SYSTEMS, AND METHODSFOR ASSESSMENT OF VESSELS” and filed Dec. 31, 2012, which is herebyincorporated by reference in its entirety. In some embodiments,co-registration and/or correlation can be completed as described in U.S.Provisional Patent Application No. 61/856,509, titled “DEVICES, SYSTEMS,AND METHODS FOR ASSESSMENT OF VESSELS” and filed Jul. 19, 2013, which ishereby incorporated by reference in its entirety. In other embodiments,co-registration and/or correlation can be completed as described inInternational Application No. PCT/IL2011/000612, titled “CO-USE OFENDOLUMINAL DATA AND EXTRALUMINAL IMAGING” and filed Jul. 28, 2011,which is hereby incorporated by reference in its entirety. Further, insome embodiments, co-registration and/or correlation can be completed asdescribed in International Application No. PCT/IL2009/001089, titled“IMAGE PROCESSING AND TOOL ACTUATION FOR MEDICAL PROCEDURES” and filedNov. 18, 2009, which is hereby incorporated by reference in itsentirety. Additionally, in other embodiments, co-registration and/orcorrelation can be completed as described in U.S. patent applicationSer. No. 12/075,244, titled “IMAGING FOR USE WITH MOVING ORGANS” andfiled Mar. 10, 2008, which is hereby incorporated by reference in itsentirety.

Referring now to FIG. 5, shown therein is an exemplary depiction ofangiogram data as may be provided to the clinician in a user interface500, such as may be provided by the computing device 172 of FIG. 4. Theuser interface 500 includes a window 502 that may be presented in thedisplay 182 as seen in FIG. 4. The window displays angiogram data thatincludes cardiac tissue 506 and vasculature 508 obtained using acontrast agent. In some embodiments, the angiogram 504 may be athree-dimensional angiogram that may be manipulated by the clinician toprovide different views, including different perspective views and/orcross-sectional views, of the patient's vasculature. During subsequentprocedures, the clinician may navigate the instruments 130 and/or 132through the patient's vasculature, collecting physiology measurementstherein. The physiology measurements may be stored in a memory of thecomputing device 172 and also displayed on the display 182. Theimage-based physiology measurements may include a dominanceclassification, a degree of occlusion of a lesion, which may beexpressed as a percent diameter stenosis, a classification of a lesion,a degree of bending of a vessel of the vessel system, a length of alesion, and/or a degree of calcification of a lesion. In particular, thestatus of the system in regards to vessel mapping, lesionidentification, and lesion classification may be seen in the windows510, 520, 530 of the user interface 500. These windows may display thestatus of the various features with an on/off indicator as shown inFIGS. 5-8. The user interface 500 also allows for selection of a certainarea of the image. In this case, no specific area is selected.

After obtaining the angiogram data, the data may be parsed by animage-processing component provided by the system 150 of FIG. 4 tosegment the patient's vasculature and estimate certain features thereof.The parsing of the data may be performed to extract image-basedphysiology measurements which may be automatically displayed without thecontinued interaction of a clinician. For example, the image-basedphysiology measurements may be extracted after an angiogram collectionprocess is complete.

When processing the angiogram data, quantitative coronary angiography(QCA) may be used to assess and identify blockages from the image-baseddata. A QCA process may be initiated automatically to identify anyblockages. While the clinician may provide a qualitative evaluationbased on his or her own experience, the information from the QCA processmay be used in subsequent steps to automatically generate an objectiveintervention recommendation. As is discussed in further detail below,co-registration techniques incorporated herein by reference and othersthat may be known to those of skill in the art may be used toco-register physiology measurements to specific positions in a model ofthe patient's vasculature 508 generated from the angiogram 504 presentedin the window 502.

Now referring to FIG. 6, the user interface 500 displays data from thevarious sources as collected and analyzed by the system 150. Inparticular, the vessel of the patient is actively mapped according tothe co-registered data. The status of the system is shown as “on” in thewindow 510 pertaining to vessel mapping. The user interface 500 maydisplay the mapped vessels as a colored region. The user is able to lookat specific regions of the mapped area to observe associated pressurereadings and lesion identification and classification. Further, as aresult of the vessel mapping the system may label the vesselsaccordingly. For example, in the illustrated embodiment, the rightcoronary artery is labeled “RCA,” the left main artery is labeled “LeftMain,” the left circumflex artery is labeled “LCX,” the marginalbranches are labeled “M1” and “M2,” the left anterior descending arteryis labeled “LAD,” and the diagonal branch is labeled “D1.” It isunderstood that any vessels, including arteries and veins, may belabeled in a similar manner. Further, a user may select the vessels ofinterest such that only those vessels are labeled by the system.

Automatic mapping of the vessel system by the system 150 may beaccomplished upon performing an image-recognition process on theangiogram information such as that depicted in the user interface 500 ofFIG. 5. The angiogram information may include information characterizingor describing features of the vessel system such as the contours,location, branches, and other features of the vessels to automaticallyidentify individual vessels within the patient's vasculature. In thisway, a model of the patient's vasculature may be generated and parsed toidentify specific sections which a user may observe. Particular vesselswhich may be identified and mapped by the system 150 include, but arenot limited to, right coronary artery (RCA), left main coronary artery(LCA), circumflex coronary artery, left anterior descending (LAD), RCAproximal, RCA mid, RCA distal, LAD proximal, LAD mid, LAD apical, firstdiagonal, additional first diagonal, second diagonal, additional seconddiagonal, proximal circumflex, intermediate/anterolateral, obtusemarginal, distal circumflex, left posterolateral, posterior descending,among others.

Markers 540 may be used in conjunction with the mapping of the vesselsystem. As seen in FIG. 6, an FFR reading is shown at the selected areaof the LCA with marker 540. Other physiological readings or anatomicallabels may be displayed by markers 540. Markers 540 can also bepositioned automatically based on the physiology measurements. Thesystem can be configured to select locations within the vessel that areclinically significant based on the diagnostic information (e.g.,locations where the physiology measurements change significantly, suchas points at which pressure changes). Similarly, the markers 540 may beprovided for various predefined segments of the patient's vasculature.Markers 540 may also be automatically generated based on the angiogramdata using image-recognition and modeling techniques. In someembodiments, markers 540 are included automatically by the system 150upon performing an image-recognition process on the angiograminformation. The angiogram information may include, informationcharacterizing or describing features of the vessel system such as thecontours, location, branches, and other features of the vessel(s) toautomatically identify individual vessels within the patient'svasculature. In this way, a model of the patient's vasculature may begenerated and parsed to identify specific sections warranting theappropriate label.

It is understood that numerous other visualization techniques may beutilized to convey the information of FIG. 6 in the context of anangiographic image or other image of the vessel (including bothintravascular and extravascular imaging techniques, such as IVUS, OCT,ICE, CTA, etc.) to help the user evaluate the vessel. In that regard,while the examples of the present disclosure are provided with respectto angiographic images, it is understood that the concepts are equallyapplicable to other types of vessel imaging techniques, includingintravascular and extravascular imaging. In some instances, a user isable to select what information should be included or excluded from thedisplayed image. In that regard, it should be noted that thesevisualization techniques related to conveying the pressure measurementdata in the context of an angiographic or other image of the vessel canbe utilized individually and in any combinations. For example, in someimplementations a user is able to select what visualization mode(s)and/or portions thereof will be utilized and the system outputs thedisplay accordingly. Further, in some implementations the user is ableto manually annotate the displayed image to include notes and/or inputone or more of the measured parameters.

The images of vessels in FIG. 6 can include three-dimensional,two-dimensional, angiographic, a computed tomography angiographic (CTA),and/or other suitable forms of images. In some embodiments, athree-dimensional image may be rotated about a vertical axis. In someembodiments, a two-dimensional image may include multiple views about avertical axis such that different two-dimensional views are shown whenthe image is rotated. In some implementations, the three dimensionalmodel is displayed adjacent to a corresponding two dimensional depictionof the vessel. In that regard, the user may select both the type ofdepiction(s) (two dimensional (including imaging modality type) and/orthree dimensional) along with what visualization mode(s) and/or portionsthereof will be utilized. The system will output a corresponding displaybased on the user's preferences/selections and/or system defaults.

FIG. 7 shows an exemplary user interface 500 with the vessel mapping andlesion identification features activated. As in FIG. 6, the windows 510,520 corresponding to the features are labeled as “on.” In the embodimentshown, the lesion identification feature displays regions of interest522, 524 where lesions are likely to be located. The identification ofthese area may be based on physiology measurements. The system 150 canbe configured to select locations within the vessel that are clinicallysignificant based on the diagnostic information (e.g., locations wherethe physiology measurements change significantly, such as points atwhich pressure changes). Similarly, the one or more regions of interestmay be based on anatomical data the signals heightened risk of lesions,such as the narrowing of a vessel. As seen in FIG. 7, regions ofinterest 522, 524 can be identified without classifying the lesions thatare likely to exist at the defined areas. In this case, window 530remains blank.

Referring now to FIG. 8, shown therein is a depiction of a userinterface 600 with activated features of vessel mapping, lesionidentification, and lesion classification. In this example, the system150 has identified two regions of interest 522, 524 and has furtherclassified the potential lesions on window 530 and in on the userinterface 500 with prompts 580, 590. The classification of the diffuselesions is based on the steady pressure drop over a long portion of thevessel, while the classification of the focal lesion is based on a sharppressure drop at certain location on the vessel. Markers 540, 560 may beused in lesion classification. Additionally, markers 540, 560 may beused to further study the identified lesions. For example, maker 560shows a low pressure reading at the center of the region of interest 524which may further define the classification as a severe focal lesion.Classifications of lesions will be further discussed in relation to FIG.9.

Referring now to FIG. 9, shown therein is a depiction of a userinterface 600 for evaluating a vessel based on obtained physiologymeasurements (as depicted, pressure measurements, but may also includeflow volume, flow velocity, and/or other intravascular physiologymeasurements or calculations based thereon) according to embodiments ofthe present disclosure. The user interface may be displayed on atouch-sensitive display. A clinician can view, analyze, and interactwith the pressure data and/or visual representations of the pressuredata.

Referring more specifically to FIG. 9, shown therein is a screen display200 according to an embodiment of the present disclosure. The screendisplay 200 includes multiple tabs, including an iFR tab 202, an FFR tab204, a patient tab 206, and a settings tab 208. In FIG. 9, the iFR tab202 has been selected and displayed to a user. As shown, the iFR tab 202includes a graph 210 and a corresponding pressure waveform plot 212. Thescreen display 200 also includes a window 214 that shows a calculatedpressure ratio (e.g., FFR, iFR, or otherwise). The screen display 200also includes a window 216 showing the runs or pullbacks available fordisplay to the user. In the illustrated embodiment, two different runsare available and identified by a corresponding time stamp. In thatregard, a user can select the desired run from the window 216 and thedata shown in the graph 210 and pressure waveform plot 212 will updateaccordingly.

The screen display 200 also includes zoom buttons 218, 220 that allow auser to zoom out or in, respectively, on the graph 210 and the pressurewaveform plot 212. To this end, the screen display 200 includes a ruler222 showing the relative scale of the graph 210 and the pressurewaveform plot 212. In some instances, the ruler 222 provides adimensional scale of the graphical display of the graph 210 and/or thepressure waveform plot 212 relative to the vessel length and/or thepullback length. The scale of the ruler 222 automatically updates inresponse to selective actuation of the zoom buttons 218, 220 in someimplementations.

The screen display 200 also includes a slider 224. The slider 224 allowsthe user to move along the length of the vessel and/or the correspondingpullback data. For example, in some instances the left end of the slider224 corresponds to the beginning of the pullback and the right end ofthe slider corresponds to the end of the pullback. By moving the slider224 between the first and second ends, a user can see correspondingportions of the pressure data in the graph 210 and the pressure waveformplot 212. Accordingly, a user can focus on certain portions of thevessel and pullback data using the zoom buttons 218, 220 in combinationwith the slider 224. In some instances, the numerical value of thepressure ratio displayed in window 214 is updated based on the positionof the slider and/or. In that regard, in some instances the numericalvalue of the pressure ratio displayed in window 214 is based solely onthe pressure data being displayed in the graph 210 and the pressurewaveform plot 212. However, in other instances the numerical value ofthe pressure ratio displayed in window 214 is based one of or acombination of the pressure data being displayed in the graph 210 andthe pressure waveform plot 212 and pressure data not displayed in thegraph 210 and the pressure waveform plot 212.

In that regard, the graph 210 and pressure waveform plot 212 of screendisplay 200 illustrate aspects of pressure measurements obtained as oneinstrument is moved through the vessel and another instrument ismaintained at a fixed location. In that regard, in some instances thepressure measurements are representative of a pressure ratio between afixed location within the vessel and the moving position of theinstrument as the instrument is moved through the vessel. For example,in some instances a proximal pressure measurement is obtained at a fixedlocation within the vessel while the instrument is pulled back throughthe vessel from a first position distal of the position where theproximal pressure measurement is obtained to a second position moreproximal than the first position (i.e., closer to the fixed position ofthe proximal pressure measurement). For clarity in understanding theconcepts of the present disclosure, this arrangement will be utilized todescribe many of the embodiments of the present disclosure. However, itis understood that the concepts are equally applicable to otherarrangements. For example, in some instances, the instrument is pushedthrough the vessel from a first position distal of the proximal pressuremeasurement location to a second position further distal (i.e., furtheraway from the fixed position of the proximal pressure measurement). Inother instances, a distal pressure measurement is obtained at a fixedlocation within the vessel and the instrument is pulled back through thevessel from a first position proximal of the fixed location of thedistal pressure measurement to a second position more proximal than thefirst position (i.e., further away from the fixed position of the distalpressure measurement). In still other instances, a distal pressuremeasurement is obtained at a fixed location within the vessel and theinstrument is pushed through the vessel from a first position proximalof the fixed location of the distal pressure measurement to a secondposition less proximal than the first position (i.e., closer the fixedposition of the distal pressure measurement).

The pressure differential between the two pressure measurements withinthe vessel (e.g., a fixed location pressure measurement and a movingpressure measurement) is calculated as a ratio of the two pressuremeasurements (e.g., the moving pressure measurement divided by the fixedlocation pressure measurement), in some instances. In some instances,the pressure differential is calculated for each heartbeat cycle of thepatient. In that regard, the calculated pressure differential is theaverage pressure differential across a heartbeat cycle in someembodiments. For example, in some instances where a hyperemic agent isapplied to the patient, the average pressure differential across theheartbeat cycle is utilized to calculate the pressure differential. Inother embodiments, only a portion of the heartbeat cycle is utilized tocalculate the pressure differential. The pressure differential is anaverage over the portion or diagnostic window of the heartbeat cycle, insome instances.

In some embodiments a diagnostic window is selected using one or more ofthe techniques described in U.S. patent application Ser. No. 13/460,296,filed Apr. 30, 2012 and titled “DEVICES, SYSTEMS, AND METHODS FORASSESSING A VESSEL,” which is hereby incorporated by reference in itsentirety. As discussed therein, the diagnostic windows and associatedtechniques are particularly suitable for use without application of ahyperemic agent to the patient. In general, the diagnostic window forevaluating differential pressure across a stenosis without the use of ahyperemic agent is identified based on characteristics and/or componentsof one or more of proximal pressure measurements, distal pressuremeasurements, proximal velocity measurements, distal velocitymeasurements, ECG waveforms, and/or other identifiable and/or measurableaspects of vessel performance. In that regard, various signal processingand/or computational techniques can be applied to the characteristicsand/or components of one or more of proximal pressure measurements,distal pressure measurements, proximal velocity measurements, distalvelocity measurements, ECG waveforms, and/or other identifiable and/ormeasurable aspects of vessel performance to identify a suitablediagnostic window.

In the illustrated embodiment of FIG. 9, the graph 210 shows thepressure ratio over time. In particular, the graph 210 shows thepressure ratio calculated over the time of a pullback. Morespecifically, the graph 210 shows an iFR pressure ratio value during apullback. In that regard, the iFR pressure ratio may be calculated asdescribed in one or more of PCT Patent Application Publication No. WO2012/093260, filed Jan. 6, 2012 and titled “APPARATUS AND METHOD OFCHARACTERISING A NARROWING IN A FLUID FILLED TUBE,” PCT PatentApplication Publication No. WO 2012/093266, filed Jan. 6, 2012 andtitled “APPARATUS AND METHOD OF ASSESSING A NARROWING IN A FLUID FILLEDTUBE,” U.S. patent application Ser. No. 13/460,296, filed Apr. 30, 2012and titled “DEVICES, SYSTEMS, AND METHODS FOR ASSESSING A VESSEL,” PCTPatent Application Publication No. WO 2013/028612, filed Aug. 20, 2012and titled “DEVICES, SYSTEMS, AND METHODS FOR VISUALLY DEPICTING AVESSEL AND EVALUATING TREATMENT OPTIONS,” U.S. Provisional PatentApplication No. 61/856,509, filed Jul. 19, 2013 and titled “DEVICES,SYSTEMS, AND METHODS FOR ASSESSMENT OF VESSELS,” and U.S. ProvisionalPatent Application No. 61/856,518, filed Jul. 19, 2013 and titled“DEVICES, SYSTEMS, AND METHODS FOR ASSESSING A VESSEL WITH AUTOMATEDDRIFT CORRECTION,” each of which is hereby incorporated by reference inits entirety.

The graph 210 can illustrate the pressure ratio and/or the underlyingpressure measurements in any suitable way. Generally speaking, therepresentation of the data in graph 210 can be utilized to identifygradients/changes in the pressure ratio and/or the underlying pressuremeasurements that can be indicative of a significant lesion in thevessel. In that regard, the visual representation of the data caninclude the pressure measurement(s); a ratio of the pressuremeasurements; a difference in the pressure measurements; a gradient ofthe pressure measurement(s), the ratio of the pressure measurements,and/or the difference in the pressure measurements; first or secondderivatives of the pressure measurement(s), the ratio of the pressuremeasurements, and/or the difference in the pressure measurements; and/orcombinations thereof.

Likewise, the pressure waveform plot 212 shows the correspondingpressure data. In that regard, the pressure waveform plot 212 caninclude the pressure waveform for the pressure sensing device movedthrough the vessel during the pullback, the pressure waveform for thestationary pressure sensing device, or both. In the illustratedembodiment, the pressure waveform plot 212 includes the pressurewaveforms for both. In some instances the pressure waveform plot 212 isaugmented to highlight or otherwise accentuate the pressure datacorresponding to the diagnostic window utilized for the pressure ratiocalculations.

As shown in FIG. 9, the screen display 200 includes a button 226indicating that the data is being displayed in a “Live” mode, whichindicates that the screen display 200, including graph 210, pressurewaveform plot 212, and/or the window 214, is being updated in real timeas a procedure is being performed. In other instances, the button 226 ofthe screen display 200 will indicated that it is in “Playback” or“Review” mode, which indicates that the screen display 200 is showingdata obtained previously. With respect to the “Live” mode, it should benoted that the determination of the diagnostic window and/or thecalculation of the pressure differential are performed in approximatelyreal time or live to identify the diagnostic window of the heartbeatcycle and calculate the pressure differential. In that regard,calculating the pressure differential in “real time” or “live” withinthe context of the present disclosure is understood to encompasscalculations that occur within 10 seconds of data acquisition. It isrecognized, however, that often “real time” or “live” calculations areperformed within 1 second of data acquisition. In some instances, the“real time” or “live” calculations are performed concurrent with dataacquisition. In some instances the calculations are performed by aprocessor in the delays between data acquisitions. For example, if datais acquired from the pressure sensing devices for 1 ms every 5 ms, thenin the 4 ms between data acquisitions the processor can perform thecalculations. It is understood that these timings are for example onlyand that data acquisition rates, processing times, and/or otherparameters surrounding the calculations will vary. In other embodiments,the pressure differential calculation is performed 10 or more secondsafter data acquisition. For example, in some embodiments, the datautilized to identify the diagnostic window and/or calculate the pressuredifferential are stored for later analysis.

By comparing the calculated pressure differential to a threshold orpredetermined value, a physician or other treating medical personnel candetermine what, if any, treatment should be administered. In thatregard, in some instances, a calculated pressure differential above athreshold value (e.g., 0.80 on a scale of 0.00 to 1.00) is indicative ofa first treatment mode (e.g., no treatment, drug therapy, etc.), while acalculated pressure differential below the threshold value is indicativeof a second, more invasive treatment mode (e.g., angioplasty, stent,etc.). In some instances, the threshold value is a fixed, preset value.In other instances, the threshold value is selected for a particularpatient and/or a particular stenosis of a patient. In that regard, thethreshold value for a particular patient may be based on one or more ofempirical data, patient characteristics, patient history, physicianpreference, available treatment options, and/or other parameters.

Also shown on FIG. 9 is region of interest 630. The region of interest630 may be assigned by the system 150 based on anomalous readings fromthe instruments such as drastic pressure changes in the vessel. In thisembodiment, the region of interest 630 is centered around a sharppressure change in the vessel. When such an region of interest 630 isidentified by the system 150, the screen display 200 may show one ormore options for taking further diagnostic measurements of the region ofinterest 630. Therefore, the screen display 200 as shown in FIG. 9prompts a medical professional to perform an IVUS measurement on theidentified section of the vessel which may be further confirmed by athree-dimensional angiogram.

The coloring and/or other visually distinguishing aspect of the pressuredifferential measurements depicted in graph 210 and/or window 214 of thescreen display 200 of FIG. 9 are configured based on the threshold valuein some instances. For example, a first color (e.g., green, white, orotherwise) can be utilized to represent values well above the thresholdvalue (e.g., where the threshold value is 0.80 on a scale of 0.00 to1.00, values above 0.90), a second color (e.g., yellow, gray, orotherwise) can be utilized to represent values near but above thethreshold value (e.g., where the threshold value is 0.80 on a scale of0.00 to 1.00, values between 0.81 and 0.90), and a third color (e.g.,red, black, or otherwise) can be utilized to represent values equal toor below the threshold value (e.g., where the threshold value is 0.80 ona scale of 0.00 to 1.00, values of 0.80 and below). Further, in someinstances the graph 210 includes one or more horizontal lines or otherdepictions representing the threshold value(s). It is appreciated thatany number of color combinations, scalings, categories, and/or othercharacteristics can be utilized to visually represent the relative valueof the pressure differential to the threshold value. However, for thesake of brevity Applicants will not explicitly describe the numerousvariations herein.

FIG. 10 shows diagrams of several classifications of lesions that may beidentified by the system 150, including “focal,” “moderate,” “severe,”“diffuse,” “long,” “short,” “multiple,” and “multi.” Lesion 810 is madeup of plaque buildup on both an upper portion 116 and lower portion 118of a vessel 100. A decrease in the distance 802 between the upper andlower portions 116, 118 of the plaque buildup leads to a decrease inpressure because the plaque buildup decreases the available space forfluid to flow through the vessel 100. This pressure drop may also bereferred to a as the functional intensity of the lesion. Theclassification of the lesion can be derived from the functionalintensity and the length of the pressure drop across the vessel 100. Inparticular, the functional intensity or slope of the pressure loss maybe mapped to a length of the vessel using techniques such asco-registration of physiologic measurements such as FFR, iFR, CFR, andangiography, and the results of the analysis may be compared to aclassification index containing the lesions classifications as describedbelow.

Lesion 810 causes a sharp pressure loss over a relatively short lengthand is classified as “focal.” Focal lesions may vary greatly inseverity, and may be further classified according to how much theydecrease the cross section if the vessel 100. This may be measured byeither a distance 802 or a percentage of the vessel that is constricted.Because lesions may occur in vessels of many different sizes,classification by a percentage may be favored. In some cases, “moderate”focal lesions narrow the vessel 100 by 20-60%, whereas “severe” focallesions narrow the vessel 100 by 60-100%.

In contrast to the focal lesion focal lesions, other lesions cause agradual pressure drop over a longer length of the vessel. For example,lesion 820 is classified as “diffuse.” As shown, diffuse lesions oftenexhibit uneven plaque buildup along the length of the vessel 100.Diffuse lesions may be further classified based on their length 806(i.e., the distance along the vessel 100 that the plaque extends on bothsides of the vessel). In one embodiment, lesions with a length of over 5mm are classified as “long,” while lesions measuring 5 mm or less areclassified as “short.” In some instances, multiple lesions exist withina vessel 100, such as those shown in example 830. Where the lesions areclose together, example 830 may be considered as a “multiple” lesionclassification. The distance 808 between lesions may determine if theyare separate focal lesions or a combined multiple lesion. In oneembodiment, where the lesions are less than 10 mm apart, they may beconsidered as a multiple lesion. Lesion 840 shows complex plaque buildupforms on both sides of the vessel 100. In this case, two lesions overlapwithin the vessel and the lesion 840 may be classified as “multi.” Thisclassification includes multiple lesions located close together so thatthere is no distance 808 between their areas of plaque buildup, whilenarrowed sections occur at two or more points along the vessel 100. Theclassification process of the present disclosure may involve examiningthe vessel anatomy at the point of the suspected lesion. In particular,the presence of plaque around a vessel bifurcation can lead to anomalousclassifications because pressure reading may vary widely as a result ofthe bifurcation.

FIG. 11 is a flow diagram of a method 1000 of evaluating a vessel systemof a patient to identify and classify a lesion in the vessel of apatient according to an embodiment of the present disclosure. Method1000 can be implemented by a system described herein, such as system 150of FIG. 4. As illustrated in FIG. 11, the method 1000 is illustrated asa plurality of enumerated steps or operations. Embodiments of the method1000 may include additional steps or operations before, after, inbetween, or as part of the enumerated steps. At step 1002, method 1000can include obtaining image data from an image of a vessel system. Thismay be done by contacting networked storage such as an electronic healthrecord storage system to obtain image data, such as angiogram data. Theangiogram data may include a two dimensional angiographic image, a threedimensional angiographic image, and/or a computed tomographyangiographic (CTA) image. An example of the angiogram data may be seenin the user interface 500 of FIGS. 5-8, which includes the angiogram504.

At step 1004, the method 1000 can include obtaining physiologymeasurements from a first instrument and a second instrument positionedwithin the vessel of the patient while the second instrument is movedlongitudinally through the vessel from a first position to a secondposition. One or more diagnostic measurements (e.g., pressure-basedincluding FFR and iFR, flow-based including CFR, etc.) can be used togather the physiology measurements to characterize the existence and/orseverity of a lesion or lesions within the vasculature of a patient. Forexample, when FFR is used, areas of a patient's vasculature that have arelatively high FFR (e.g., greater than 0.80) are characterized as nothaving a lesion or stenosis, while areas with a relatively low FFR(e.g., less than 0.80) are characterized as having a lesion or stenosis.The physiology measurements may be obtained in a manner that provides atleast some location information associated with the measurements.

At step 1006, the method 1000 can include co-registering the physiologymeasurements with the image data to produce co-registered physiologymeasurements. The co-registered physiology measurements can be displayedin an overlaid fashion, such that the physiology measurements may bevisualized in association with the angiogram image data. An example maybe seen in the user interface 500 of FIGS. 5-8. By co-registering thephysiology measurements with the image data, the system 150 may provideadditional perspective to a clinician or clinicians. The imagery mayindicate the physical dimensions of the patient's vasculature, which maybe sufficient to identify one or more lesions therein, while thephysiology measurements indicate the impact or effect of lesions withthe vasculature. In some embodiments, co-registering the physiologymeasurements with the image data may include associating, in a datafile, each physiology measurement with a location within the vesselsystem, identifying a corresponding location for each physiologymeasurement with the image data, and associating in the co-registeredphysiology measurements data file, each physiology measurement with itscorresponding location within the image of the vessel system. In someembodiments, co-registering the physiology measurements may produce anew data file that includes the co-registered physiology measurements.

Co-registration may also be accomplished by overlaying the data fromimaging systems (such as angiographic images, x-ray images, CT images,PET images, MM images, SPECT images, and/or other two-dimensional orthree-dimensional extraluminal depictions of a patient's vasculature)with data obtained by instruments 130, 132, 152, and/or 175 of thesystem 150 (as shown in FIG. 4). In some cases, informationcharacterizing or describing features of the vessel system such as thecontours, location, branches, and other features of the vessels are usedto automatically identify individual vessels within the patient'svasculature and serve as a baseline for compiling a complete vessel mapfor a patient.

At step 1008, the method 1000 can include analyzing the co-registeredphysiological measurements to determine the classification of a lesionwithin the vessel. Potential regions of interest where a lesion may belocated are identified by the system 150 based on co-registered pressurereadings and anatomical context of the readings. Potential lesionlocations may also be based on anatomical physiological data such asunexpected narrowing of a vessel or the existence of a side branch neara stenosis. Further physiology information that may be considered in theidentification includes dominance classification, a degree of occlusionof the lesion area, a degree of bending of a vessel of the vesselsystem, a degree of calcification of the lesion area, etc. Theidentification may also be based on a comparison of currentphysiological measurements with previously recorded physiologicalmeasurements from a database. Other sources of information that formpart of the analysis and formulation of the recommendation includepatient history such as age, gender, or preexisting conditions such asdiabetes or hypertension. After identifying potential lesions, thesystem 150 classifies the lesions based on functional parameters.Generally, the classification relies on the cardiovascular pressureintensity and lesion length measurements. Classifications of lesionsthat may be identified by the system 150 include “focal,” “moderate,”“severe,” “diffuse,” “long,” “short,” “multiple,” “multi,” or othersuitable classification. The criteria for making each of theseclassifications is discussed in conjunction with FIG. 10.

At step 1010, the method 1000 can include displaying the identificationand classification of the lesion to a user. In some embodiments, thisinformation is automatically displayed on a user interface 500 such asthat shown in FIGS. 5-8. The identification and classification may beread by medical professionals during the course of a procedure to helpguide diagnoses. Additionally, the identification and classification maybe used as an educational too. For instance, the identification of thelesion and factors used by the system 150 in the analysis used toformulate the identification may be presented to a patient, or thefamily members or guardian of a patient to help explain the reasoning ofthe medical professional or the likelihood of future procedures.

Persons skilled in the art will also recognize that the apparatus,systems, and methods described above can be modified in various ways.Accordingly, persons of ordinary skill in the art will appreciate thatthe embodiments encompassed by the present disclosure are not limited tothe particular exemplary embodiments described above. In that regard,although illustrative embodiments have been shown and described, a widerange of modification, change, and substitution is contemplated in theforegoing disclosure. It is understood that such variations may be madeto the foregoing without departing from the scope of the presentdisclosure. Accordingly, it is appropriate that the appended claims beconstrued broadly and in a manner consistent with the presentdisclosure.

What is claimed is:
 1. A system, comprising: a guidewire or catheterconfigured to be positioned within a blood vessel of a patient, whereinthe guidewire or catheter comprises a pressure sensor configured toacquire pressure measurements of the blood vessel, wherein the pressuresensor is coupled to a distal portion of the guidewire or catheter; anda processor configured for communication with a display and theguidewire or catheter, wherein the processor is configured to:communicate with an x-ray imaging device to obtain an x-ray image of theblood vessel; control the guidewire or catheter to acquire the pressuremeasurements via the pressure sensor; determine, based on the pressuremeasurements, a plurality of pressure ratios associated with a pluralityof locations within the blood vessel; co-register the plurality ofpressure ratios with the x-ray image such that each pressure ratio ofthe plurality of pressure ratios is associated with a correspondinglocation of the blood vessel; identify a position of a lesion within theblood vessel based on the plurality of co-registered pressure ratios;and output, to the display, a screen display comprising the x-ray imageand a graphical representation of the position of the lesion, whereinthe graphical representation is disposed at the position of the lesionin the x-ray image.
 2. The system of claim 1, wherein the position ofthe lesion spans a length of the blood vessel, and wherein the graphicalrepresentation spans the length of the blood vessel in the x-ray image.3. The system of claim 1, wherein the graphical representation isoverlaid on the blood vessel in the screen display.
 4. The system ofclaim 1, wherein the processor is configured to: receive a user inputactivating identification of the position of the lesion; identify theposition of the lesion in response to the user input; and include thegraphical representation in the screen display in response to the userinput.
 5. The system of claim 4, wherein the screen display comprises anactivation status corresponding to identification of the position of thelesion, wherein, in response to the user input, the screen displaycomprises an on state for the activation status.
 6. The system of claim1, wherein the processor is configured to: receive a user inputdeactivating identification of the position of the lesion; and outputthe screen display without the graphical representation.
 7. The systemof claim 6, wherein the screen display comprises an activation statuscorresponding to identification of the position of the lesion, wherein,in response to the user input, the screen display comprises an off statefor the activation status.
 8. The system of claim 1, wherein theprocessor is configured to identify the position of the lesion based ona change in the plurality of co-registered pressure ratios between theplurality of locations.
 9. The system of claim 1, wherein the processoris configured to analyze the x-ray image to identify an anatomical namefor the blood vessel, and wherein the screen display comprises theanatomical name.
 10. The system of claim 9, wherein the processorutilizes a computer aided detection algorithm to identify the anatomicalname for the blood vessel.
 11. The system of claim 1, wherein the x-rayimage includes at least one of a two-dimensional angiographic image, athree-dimensional angiographic image, or a computed tomographyangiographic (CTA) image.
 12. The system of claim 1, wherein theprocessor is configured to determine a classification of the lesion, andwherein the screen display comprises the classification.